提交后PHP重定向到同一页面

Question

我需要你对我的基本php练习的帮助。请检查下面是我的代码。我已经通过不同的php文件添加了我的表单的动作。提交表格后我想要的。我将在显示此感谢消息后再次成功提交此消息，重定向到index.php页面，但现在此页面不重定向。它保持联系.php页面。感谢。

    <?php 
    if(isset($_POST['submit'])){

        $sub = "New Message";
        $to = "musar001@gmail.com";
        $email = $_POST['email'];
        $message = "Your Name:" . " " .$_POST['name'] . "\r\n";
        $message .= "Your E-mail:" . " " . $_POST['email'] . "\r\n";
        $message .= "Mobile Number:" . " " . $_POST['mobile'] . "\r\n";
        $message .= "Country Name:" . " " . $_POST['country'] . "\r\n";
        $message .= "I have dog(s):" . " " . $_POST['dog'] . "\r\n";
        $message .= "And Cat(s):" . " " . $_POST['cat'] . "\r\n";
        $headers = "From: $email" . "\r\n";

        $success = mail($to, $sub, $message, $headers);

        if(isset($_POST) && $success) {
            echo "<h2>Successfully Submitted. Thanks.</h2>";
//If I use header function I can't see thank you message. 
 // header('location: index.php');
        }
    }

＆GT;

html代码的几个例子。

<form action="contact.php" method="POST" id="contactform" class="wpcf7-form contactform-v2">

   <div class="row">
      <div class="col-xs-6 col-sm-6">

        <p class="contact-form-author">

  <input type="text" required="required" value="" name="name" id="name" placeholder="Your Name *"></p>

    </div>

          <div class="col-xs-6 col-sm-6">

            <p class="contact-form-email">

              <input type="email" required="required" value="" name="email" id="email" placeholder="Your Email *"></p>

          </div>

      </div>
</form>

我没有找到任何问题的答案。